diff --git a/reference/network/functions/setcookie.xml b/reference/network/functions/setcookie.xml
index d2f9a34e669b..0caf1125a50b 100644
--- a/reference/network/functions/setcookie.xml
+++ b/reference/network/functions/setcookie.xml
@@ -178,6 +178,15 @@
         </para>
        </note>
       </para>
+      <para>
+       <note>
+        <para>
+         If <literal>samesite</literal> is <literal>None</literal> then
+         <literal>secure</literal> must also be enabled or the cookie will be
+         blocked by the client.
+        </para>
+       </note>
+      </para>
      </listitem>
     </varlistentry>
    </variablelist>